Battery systems having a plurality of cells are used in particular as energy stores for the drive for electric and hybrid vehicles. As overload protection, for example in the event of a short circuit in an electrical consumer assigned to the battery system, usually a fuse is arranged in the circuit between the battery system and the electrical consumer. If the current flowing in the circuit between the battery system and the electrical consumer reaches a limit value, the fuse blows, and thus, disconnects the circuit. If the cause of the increased current is eliminated, the battery system and the electrical consumer assigned to the battery system may be brought into operation again by replacing the fuse. Detecting whether the fuse has blown is a way of facilitating the maintenance of the vehicle having such a battery system.
Laid-open Japanese Patent Publication No. JP 2010-146773A discloses a battery system in which a monitoring apparatus for a battery pack is specified, in which tripping of a fuse is identified by voltage measurement at two measurement points within the battery pack and evaluation of the voltage measurement by a microcomputer. One disadvantage with this system is that a dedicated voltage measurement is required for detecting whether the fuse has blown. This firstly increases the complexity involved in the installation of the battery system since additional measuring lines are required. It also increases the complexity of the monitoring apparatus since additional signals need to be detected and converted into a suitable form. Such additional complexity is additionally multiplied when a plurality of electrical consumers having a respectively dedicated fuse are assigned to the battery system.